


Explore

by snick_snack



Series: Discovery [2]
Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Anal Sex, First Time, M/M
Language: English
Status: Completed
Published: 2019-10-05
Updated: 2019-10-05
Packaged: 2020-11-24 03:47:49
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,946
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20901143
Author URL: https://archiveofourown.org/users/snick_snack/pseuds/snick_snack
Summary: Byleth and Seteth spend an evening together.Set between 36 and 37 vaguely





	Explore

**Author's Note:**

> Instead of writing the next chapter in Discovery, my brain was like "omg sexy time" 
> 
> Between chapters 36 and 37 (written well before i got to that point~) 
> 
> Fell free to hit me up on tumblr @myswordhandtwitches or on twitter @snick_snack_

Byleth pushed Seteth up against the door in his room, their mouths attached to each other, almost frantic. Or he felt frantic. He had never felt like this before.

He felt like he was on fire. A slow burn that was honestly kind of pleasant. It drew him closer to Seteth, made he want more of the man. His body almost ached for more.

“Seteth,” Byleth pulled back, trying to calm his breathing. “I’ve never….”

Seteth gave him a sweet kiss, smiling lightly. “It’s okay. I’ve never been with a man. But we can figure it out together.”

Nodding, Byleth pulled him in again, his hand snaking up into his hair. Ever since he had got more adventurous while kissing him, he had discovered Seteth’s hair was one of his favorite things. It always looked neat, yes, but it was soft and delightful to touch as well. And playing with it always made Seteth give him a special kind of look that made his heart burn. Warm, with something else below the surface. He’d never been able to place it, until recently. 

Feeling this way was brand new to him. His relationship with Seteth had grown stronger over the last few months, every day feeling a bit better than the last. The war still raged around them but when they had time to spend together nothing could touch them.

And recently, he had had certain kinds of thoughts about the man. Thoughts he’d never had before. They had left him confused and anxious, in a way. 

Tonight, he had planned to spend the evening in the garden with Seteth, perhaps a walk later to enjoy the night air and gaze at the stars, but that hadn’t happened.

Seteth had greeted him with a kiss, and on an impulse, Byleth deepened it. He hadn’t planned on it, but the moment it happened, his body reacted. Seteth was, as always, open to it, simply closing the door behind them. 

And now they were here, Seteth slowly pushing his hands under Byleth’s shirt. He was gentle, his hands warm as they wrapped around his skin. Feeling his fingers and nails slowly drag up his back, he pulled back, laying his head on Seteth’s shoulder, groaning. 

Seteth rubbed circles on his skin, comforting him. “We can go as slow as you like, my love.” He whispered into his ear, his voice already low and a little husky. 

My love. Byleth knew he loved Seteth. At least, he thought he did. He knew he’d do absolutely anything for him and to protect him. But he wasn’t the best at putting names to feelings. He definitely liked hearing the pet name, though.

Byleth pulled back a bit, reaching up to the buttons on his shirt. He quickly undid one himself, before Seteth pulled his hands back, smirking at him.

“No, allow me.” Seteth shifted so he could press Byleth against the wall now. Giving him a gentle, burning kiss, he began to move down his jaw. As his lips began to work his jaw and neck, his hands went to work too. He was agonizing slow, unbuttoning each button with such unnecessary care. It was almost like Seteth was torturing him. 

Seteth was getting to the last two as his moved his lips down once more. Right above his collarbone. Byleth leaned his head back, his breath catching in his throat. His fingers tightened in Seteth’s hair, almost of their own free will. 

He could feel the grin on Seteth’s mouth. Of course he could. It was pressed against his skin. Seteth’s breath was hot on his chest, burning him from the outside in. 

Finally, Seteth finished with his shirt, and reached up to help push it off his shoulders, but Byleth was too eager, simply shrugging it off and tossing it in the corner of his room. He heard the other man give a breathy laugh before letting his hands fall back to his skin. 

Being shirtless around Seteth was new. Not that he ever really walked around without clothes. But it was different with him. Seteth’s hand roamed his chest and stomach, eyes following them. It was almost embarrassing, being looked at like that. 

Seteth’s hands lingered around his shoulders, tracing the muscles running toward his back and chest. Byleth watched Seteth’s face as his eyes got darker. And his lips…. He had always been a fan, but right now, he felt like he needed them. 

Cutting Seteth’s ogling off, Byleth pulled his mouth in again. Let his hands fall to his shoulders, Byleth pressed his body up into Seteth’s, his chest meeting cool cloth. Oh right. 

He fumbled with his fingers, searching for the buttons of his shirt without moving away. Eventually, he found them, quickly undoing them and pushing his hand deeper into the garment. Seteth’s skin was as warm as he felt, his hand burning as he slid his fingers around his ribs. 

“You can take it off, you know.” Seteth pulled back a fraction to say. Byleth just brought him back in. He did take a moment to move up and push the shirt off his shoulders, however, letting it fall to the floor. 

Now that there was no barrier between them, Byleth pulled Seteth as close as he could. His hand reached up Seteth’s hair again, passing over his pulse point. 

Of course, he knew Seteth had a heartbeat. They had laid close to each other many times, Seteth resting his head on Byleth’s shoulder. He’d felt his heart beat through his neck as he ran his fingers through his hair. It was a strange sensation at first, but it was natural. It wasn’t his fault he didn’t have one. 

But now the point was hot and pounding. Remembering what Seteth had done just moments ago, Byleth dragged his lips away from his, and moved down, giving a short kiss under Seteth’s ear before moving to the point of his fixation. 

Almost immediately, he felt Seteth’s chest shudder. Something about it shot through his body, driving something lower in his stomach. Testing it again, he decided to use his tongue, dragging it across the point of Seteth’s neck, tasting his warm skin. A short groan fell from Seteth’s mouth, spurring him on again. 

“Byleth….” His name was barely audible, more of just a breath leaving Seteth’s lungs. 

Byleth himself shuddered at the sound. He almost forgot about what had brought that out. He had to take a step back.

For the first time, he actually took in Seteth’s upper body. Of course Seteth was strong, they fought side by side often, but seeing the muscles beneath his armor was breathtaking. His strong arms that had held him more times than he could remember right now, biceps swelling with hard-earned muscle. His chest had always looked built and thick, and without his clothes, it definitely was. His pecs were hard under Byleth’s curious fingers. Byleth let his eyes drift lower, taking in the train of sparse green hair on his lower stomach, leading down into his pants. 

He swallowed hard, staring at it. He wanted to say something, to compliment him on his body, but all he could do was stare. 

Seteth chuckled to himself, reaching for Byleth’s hands. “Never did I think you would actually be speechless.” He leaned in to kiss his cheek sweetly. “But talking doesn’t appear to be what you want, is it?” 

His voice was like velvet on ears. Gently, Seteth pulled them both toward his bed. He sat down, pulling Byleth down onto his lap. 

Oh.

The angle he had let him feel something stiff in Seteth’s pants. He knew that’s where this was leading, but somehow he had forgotten. But now he was all too aware of his situation in his own pants. 

He let his hands drift down to Seteth’s body, taking in the way his abdominal muscles clenched and relaxed as he went lower. Finally, he found the button holding the cloth together at his waist. 

“Can I—” 

“Yes.” Seteth cut him off. That was probably the first time he hadn’t let Byleth complete a sentence in the entire time they’d known each other. 

He quickly undid it, the waistband loosening around Seteth’s hips. Standing up again, they both tried to push his pants out of the way, but they stopped around his knees. Oh right, the boots. Seteth seemed to have forgotten as well, giving a frustrated sigh before reaching down to slide them off. 

Finally. Seteth was left in nothing but a pair of trunks, leaving almost nothing to the imagination. Byleth wondered how he had never really taken note of how… hot… his boyfriend was. Sure, he had always admired the way his hair gleamed in the moonlight, the way his green beard shaped his chin, even if it was a strange shape for facial hair. But he had barely even thought about his body, only admiring the strength that hid within it. 

Byleth’s mind drifted as he took in the shape of Seteth’s thighs. He had imagined it, once. A few nights ago. They had had plans, but they were cut short, Flayn asking to spend time with her father. Byleth didn’t blame Seteth, it was hard to say no to her, and he wasn’t even her father. But his body had burned that night, longing for something. 

He had spent the night in his room, exploring this new sensation his body had finally woken up to. It was strange, being a full grown adult who was leading an army, but having never gone through the trials of puberty. He had simply grown taller, his voice deeper. But he guessed it was a side effect of whatever had happened to him as a baby. 

And now that his emotions had finally come to him, it was almost suffocating. 

Seteth was back on his bed, gazing at him with heavy eyes. Goddess, he wanted to kiss him.

So he did. He shifted back on his lap, his legs on either side of his hips. Gripping his jaw tight, he groaned into the kiss, feeling Seteth’s cock against his leg. Letting his hands explore again, one ended up ghosting over the fabric of his shorts. Seteth gasped, pulling back from the kiss ever so slightly. 

The sound went straight to his own. Curious what else he could do, he moved his thumb over the bulge. The breath Seteth sucked in was like fire in Byleth’s veins. Who knew he could make him sound like that? 

A firmer stroke, a full moan fell from his lips. Byleth almost moaned himself. That was possibly the most attractive thing the man had ever done. 

He was about to go in for more, but Seteth’s hand stopped him. “Byleth, you’ve forgotten something.” His eyes flicked down and back up. 

It took Byleth a moment to clear his head enough to realize what he was saying. The rest of his clothes. Of course. 

Thankfully, he hadn’t quite gotten finished dressing when Seteth showed up, so his pants slid off easy, joining the pile on the floor.

Seteth’s eyes raked over him. Byleth had rarely ever thought about his body, but now he wondered if Seteth was attracted to it. But judging by the way his hands came to rest on his thighs, he didn’t have to worry.

“What is this scar here from?” He broke the silence, thumb running over a pale scar above his knee. 

“Axe training when I was a teenager. I wasn’t very good.” 

Seteth’s hand lingered for a few moments longer, before drifting up his leg. Reaching around to the back of his thighs, Seteth pulled him back onto the bed, moving back to lean against the wall. Now that his own pants were gone, he could feel Seteth better. Straddling his hips, Byleth moved to palm at him again. 

He would never get used to the sound that caused. 

Feeling braver, encouraged by the soft sighs and moans, he teased at the waistband of Seteth’s shorts, looking for permission in his face. A single nod was given before Seteth pulled his lips back to his. 

Slipping under, he found Seteth’s cock, rigid and hot. Tentatively, he wrapped his fingers around it, feeling the girth in his hand. Seteth’s lips trembled under his. He pulled his hand down the shaft, listening intently on Seteth’s breathing. Every stroke gave him him a new sound to savor. 

He brushed his pinky finger over the tip in his excitement. He had never heard Seteth so loud before. 

Seteth tended to be fairly soft spoken, his volume never changing. There were a few moments in battle where anger would overcome him and he would shout, but nothing like this. 

This was warm and thick and immediately made Byleth squirm in his own shorts. Before he could stop himself, he pushed his hips into Seteth’s. His hand paused and his head fell to his chest as he was overcome for a moment at the feeling. 

“Byleth…” Seteth groaned in his ear, pulling his face back up. Byleth took a moment to take in Seteth’s face. He was covered in sweat, a few strands of hair sticking to his forehead. His eyes were blown out, hunger evident. His hair was a mess. 

“Seteth.” Byleth finally composed himself enough to speak. Calculating in his head, he rocked his hips back before rolling back into Seteth’s. Both of them gasped, Seteth’s hands coming down to clutch at his lower back.

Byleth stopped for a moment when he felt Seteth’s hands drift further down, pushing at his trunks. Shifting a bit, Byleth moved to take them off completely. As he did, Seteth did the same. 

Finally free of every cloth barrier between them, Seteth reached up to stroke Byleth’s face, as he often did. 

“Byleth.” He watched as Seteth swallowed hard. “I love you.” 

He could almost feel his phantom heartbeat stop. “I love you too.” He found himself saying. 

The grin that spread across Seteth’s face ached in his chest. It was true. He did love him. Goddess, this man was greatest thing to happen to him. 

Diving back in for a kiss, Byleth brought his hips back to Seteth’s. A ghost of a touch grazed his cock, and he let his head fall to Seteth’s shoulder, gasping. 

His next thrust was slopping, bringing him under Seteth, hitting a place that made him gasp and moan. 

Byleth’s mind drifted back to a book he’d found in the monastery town once at a rundown bookshop. It had been about two men, so it caught his eye. But that book had been graphic, describing the two men’s relationship in great detail. 

Recalling the actions in that tale, Byleth let his hand drift toward Seteth’s ass. He hadn’t taken note of it earlier, too focused on the muscular thighs he sat on, but feeling it now, he wondered how it hadn’t been his first thought. It was firm under his grasp, no doubt from training with wyvern. He quickly slid down the cheeks, trying to find what he was looking for.

A ring of muscle twitched under his fingers. Byleth felt Seteth tense up and moved away slightly. He looked up at the man. Seteth’s head was laying against the wall, eyes on the ceiling, his chest heaving. 

“Are you okay?” Byleth asked. 

A short nod came, and Seteth tried to catch him breath to speak. “Yes. Sorry. It’s been a long time. And you startled me.” 

“Oh. I’m sorry.”

“Don’t be.” Seteth looked down at him, his face radiating warmth and want. “But, if you’d like… that… we don’t have any oil.” Seteth’s face fell a fraction.

Oil. Right. They needed that. They hadn’t planned this so—

His thoughts stopped there. He suddenly remembered something his father gave him one birthday a few years ago. He swung his legs off Seteth and went to a bag in the corner of his room. 

Rooting around in the old thing, he found was he was looking for. A small jar of liquid. His old man had given it to him and said ‘just in case’ with a wink. At the time, he didn’t know what that meant and brushed it off, but now….

Seteth’s eyes drifted to the jar in his hand. 

“Why do you—”

“Just in case.” Byleth answered, crawling back up onto the man. The two twisted so they could fully lay on the bed, Seteth up against the pillow. 

He laughed at the answer, simply taking the jar and laying it by his head before pulling Byleth back down on him. Byleth could feel Seteth’s hard dick pressing into his hip and grinded down into it. 

Byleth had to stop himself from doing it again. He had a mission now. He reached inside the jar, coating his fingers in the slick fluid inside. 

“Seteth, please let me know if—”

“I will.” It seemed Seteth was impatient at times like this. 

Byleth tried to still the excitement trembling in his fingers. Slowly, he found that hole again and teased at it. Seteth gasped and clutched at his back. The feeling of nails digging into his skin gave him enough to push his finger in.

It was tight. Byleth’s mind immediately drifted to the idea of his cock inside, squeezed tight, and he had to pause. Taking a second to come back to the moment, he began to try and stretch out Seteth’s hole. He listened to the gasps and whines of his… lover, he supposed, listening for anything that would resemble pain. 

But that sound never came, so he slowly worked a second finger in, taking only a moment to add more oil to the mix. Seteth squirmed under him, his nails beginning to break skin. Had they always been so sharp? 

“Byleth.” Seteth grasped at his hair. “I think that’s good.” 

“I don’t want to hurt you.” Byleth said, slicking up a third finger for safe measure. “I love you.” The phrase came easy now. 

Seteth clenched around his fingers. “I want you.” 

Byleth could barely take it anymore. As gently as he could, he pulled his fingers out and moved to his cock. Spreading the oil up and down himself, it was hard to think clearly. He had Seteth, the only man he’d ever wanted under him, almost begging for him. His body was strong and powerful, and all his. 

Groaning at the thought, he brought his hips closer to Seteth’s waiting entrance. The tip of his dick teased at it, causing both men to moan together. Byleth took a moment to steady his breath and look in Seteth’s eyes before pushing in. 

The hitch in Seteth’s breath made him stop. He almost pulled back out, but Seteth shook his head, hooking a leg around his back, trapping him there. 

“Keep going.” He breathed. Byleth nodded, slowly pushing himself all the way in. 

One he was in, he had to stop again, trying to compose himself enough to remember where to go from here. Having himself so completely wrapped in everything Seteth was intense. He loved this man more than anything and to be sharing this with him was more than he could have ever hoped for. 

It wasn’t too long, but Seteth’s impatience won out. A short whine escaped his lips and Byleth took it as a sign to move.

He slowly pulled himself out, leaving just the tip in, before pushing back in. Seteth’s walls clenched around him, matching the sweet moan gracing his ears. Again and again, he took his time pushing in and out. 

“Faster, please.” Another whine, barely words, fell from Seteth’s mouth. 

Shifting his weight, he thrust in again, lips crashing on Seteth’s throat. He could feel Seteth’s heartbeat pound against his lips, and a thought came to him. 

Byleth picked up the pace, trying to match his thrusts to the power and speed of the heartbeat he could feel. Seteth’s chest heaved under his, his hands dragging down his back.

He felt like his dick was on fire, engulfed in delicious flames, contained by Seteth’s warm body. One thrust ruined his rhythm, he stuttered, pushing back in sloppily. He knew he was getting close, but the sounds tumbling from Seteth’s lips sounded like he was too. 

It was hard to think through the haze in his mind, but he tried to recall what happened in that book. He let his hands drift away from Seteth’s hips and found the base of his shaft again. 

His hands were still slick with oil so it was easy to pump him. Byleth had to pull back slightly, breathing heavy on Seteth’s skin. He leaned back a bit, seeing Seteth’s eyes clenched close as he whined under Byleth’s touch. 

The look was enough for Byleth to remember his rhythm and pound back into him, this time pumping his dick as well. Byleth could feel his body tensing up, but he pushed through it, eager to find release.

“I’m—”

“Me too.” 

Byleth came first. It took everything he had to not fall on top of Seteth. But he had to help him finish too. 

Before he had a chance to pull out, Seteth rocked his hips back into him. It was all Byleth could to keep stroking him. Seteth changed the angle of his hips and pushed back onto Byleth, hitting a spot that made him clench his teeth and finally let go.

Byleth fell, exhausted, onto Seteth’s chest, probably smearing cum on both of them. But that didn’t matter at the moment. All that mattered was being here, his head on Seteth’s chest, both of them beginning to breathe normally again. 

Seteth’s hands relaxed on his back, moving to simply hold him to his chest. He could feel Seteth’s chin on his head. 

A few moments of silence lingered before Seteth finally spoke up. “So you were expecting this?” 

“What?” Byleth turned to look up at his face. Seteth’s eyes went to the jar of oil. “Oh. No. It was given to me a few years ago. ‘Just in case’.” Byleth put air quotes around it. 

“Before you met me?” 

Byleth nodded. “I didn’t know what it was for before today.” 

Seteth paused to give him a strange look. “What?” He said as he started to laugh. “Really? There’s a picture on the jar.”

Byleth looked at it again, a pair of silhouettes displaying something very similar to what they had been doing, just moments ago. “Oh.” 

“You never cease to surprise me, Byleth.” Seteth reached up to stroke his cheek. 

Byleth leaned into the touch. “I hope you enjoyed this as much as I did.” 

Seteth smiled at him. “Of course I did.” He gave him a short, gentle kiss. “I am quite… excited… at the idea of continuing to explore this.” 

It suddenly occurred to Byleth that they could do this any time they wanted. Well, perhaps not any time. They both had their own duties and a war to tend to, and Byleth was a campus favorite. But when they had time together….

“Perhaps next time we can switch.” Byleth thought aloud, more to himself. 

He moved to lay down next to Seteth, his head still resting on his chest. His heartbeat had finally slowed to a normal pace, and it was beginning to lull him to sleep.

“I’d like that.” A hand stroked his hair, pushing it away from his forehead. He knew he probably looked like a mess, but Seteth was no better, so it was fine. “I love you, my dear Byleth.”

Byleth hummed. “And I love you. That’s the most sure I’ve ever been.”

**Author's Note:**

> Don't look at me I'm gay and thirsty
> 
> I might  
do a sequel  
maybe maybe maybe


End file.
